In recent years, numerous research papers have considered the problem of privacy protection in biometric authentication systems. When someone wants to authenticate himself, the fresh biometric data he presents has to match with the reference related to the one he claims to be. Many proposals have been made to ensure the confidentiality of the biometric data involved during this verification. Also discussed in this compilation, is the problem of finding a face recognition system that works well both under variable illumination conditions and under strictly controlled acquisition conditions. Information fusion techniques are also explored and have been widely developed in the community of voice biometrics along with several uni-modal speaker recognition algorithms.